The present invention relates to an apparatus for converting a hydrocarbon-containing flow of material into a hydrogen-enriched fluid flow with a heating device for production of a heating stream or hot gas stream used for heating purposes.
Fuel cells are electrochemical transformers of chemical energy into electrical energy. In many cases, one's goal is to convert hydrogen-rich fuel for the fuel cell unit from hydrocarbonous material, such as natural gas, gasoline, diesel, methanol or the like. In this connection, a corresponding apparatus for converting the hydrocarbon to a hydrogen-rich substance is necessary.
For example, the conversion takes place by means of reforming, or steam reforming. The steam reform of hydrocarbons is generally endothermic. The supply of the heat of reaction takes place usually through a burner. A heat flow produced hereby, that is, hot flue gas, can be used for heating of the matter flow in a first stage or converter, whereby, likewise, already in this stage, the matter flow is at least partially converted.
In addition, particulary, the heating flow, or flue gas, of the burner as well as the heat radiation coming from the burner can be used for heating of a second, hotter stage or reactor stage of the reformer.
With the two-stage steam reformers known up to this point, according to the disclosure of B. Vogel et al: “Hydrogen Generation Technologies for PEM Fuel Cells” , Proceedings of the Fuel Cell Seminar, Palm Springs, November 1998, the flue gas of a burner is already used for educt preheating as well as for heating of the reactor stages. In this example, an additional heat exchanger is placed before the reformer for using the residual heat of the flue gas.
A disadvantage of such steam reformers, however, is that at the side of the reaction zone facing away from the burner, or the second stage, the flue gas flow co-currently to the educt stream, so that among other things, the flue gas cooled by educt preheating might be brought into heating contact with hot reactor zones. Thus, an undesired, disadvantageous heat transfer from the reactor stage into the flue gas can take place, so that the reforming reaction in this reaction stage is affected disadvantageously.